N,n&#39;-bis(nitrazaalkyl)-n,n&#39;-dinitro oxamides



United States Patent 3,000,943 N,N'-BIS(NITRAZAALKYL)-N,N'-DINITROXAMIDES 0 Milton B. Frankel, Pasadena, Calif., assignor toAerojetgfiineral Corporation, Azusa, Calil., a corporation of NoDrawing. Filed June 13, 1957, Ser. No. 666,270 14 Claims. (Cl. 260--56l)This invention relates to new compositions of matter and to thepreparation thereof. In particular, the inventron relates to high energyN,N'-bis (nitrazaalkyl)-N,N'- dinitro oxamides having the generalformula:

II\TO2 IrTOr O (I) NO: NO: R 0H.-NA-0H2N-oiJ-iI-CHe-rM-N-CfirR whereineach R is a hydrogen, alkyl, or nitroalkyl radical and each A is analkylene radical.

The high energy oxamide compounds of this invention are particularlyvaluable as high explosives which can be used in any conventionalexplosive missile, projectile, rocket, or the like, as the mainexplosive charge. An example of such a missile is disclosed in UnitedStates Patent No. 2,470,162, issued May 17, 1949. One way of using thehigh explosives of this invention in a device such as that disclosed inUnited States Patent No. 2,470,162, is to pack the crystalline explosivein powder form into the warhead of the missile. Alternatively, thecrystals can be first pelletized and then packed. A charge thus preparedis sufliciently insensitive to withstand the shock entailed in theejection of a shell from a gun barrel or from a rocket launching tubeunder the pressure developed from ignition of a propellant charge, andcan be caused to explode on operation of an impact or timefusemechanisrn firing a detonating explosive such as lead azide ormercury fulminate.

The high energy oxamide compounds of my invention are prepared byreacting N,N-bis-(nitrazaalkyl) oxamides of the general formula:

N0 111 (I? (H) III N02 Example I.Preparatz'0n of N,N-bz's(3-nitraza-1-butyl)- N,N-dinitr0 oxamide A mixture of 140 ml. of 100%nitric acid, 130 ml. of concentrated sulfuric acid and 9.9 g. (0.0338mole) of N,N'-bis (3-nitraza-1-butyl) oxamide was heated at 50- 55 withgood stirring for 35 minutes. The reaction mixture was cooled and pouredon ice. The white solid which formed was collected, washed with water,and dried to yield, as the impure product, 8.8 g. of a material having amelting point of 163-165 C., which amount corresponded to a theoreticalrecovery of 67.9%. The White solid was recrystallized from acetone toproduce a material having a melting point of 168-l69 C., as the finalproduct. The calculated elemental analysis of the Patented Sept. 19,1961 product and the anaylsis as actually determined appear below:

Analysis.Calcd. for C H N O percent C, 25.13; percent H, 3.69; percentN, 29.32. Found: percent C, 25.22; percent H, 3.63; percent N, 29.11.

Reaction temperature is non-critical in the practice of this invention,the only eifect of temperature variation being a corresponding increaseor decrease in reaction rate.

The N,N-bis (nitrazaalkyl) oxamides useful as starting materials forpurposes of this invention are obtained by condensing nitraza amines,such as 3-nitraza-l-butylamine, with esters of oxalic acid, such asethyl oxalate, as more fully disclosed in my copending U.S. patentapplication Serial No. 666,269, filed concurrently with the presentapplication.

The nitraza amines useful as starting materials for the preparation ofthe N,N'-bis (nitrazaalkyl) oxamides are generated from theircorresponding strong mineral acid salts by neutralizing the strongmineral acid salts with inorganic basic salts, as for example hydroxidesor carbonates of alkali or alkaline earth minerals such as sodium,calcium, etc. This method of generating nitraza amines from their strongmineral acid, i.e. hydrochloric acid, nitric acid, or the like, salts ismore fully disclosed in my copending U.S. patent application Serial No.666,- 273, filed concurrently with the present application.

The strong mineral acid salts of the nitraza amines suitable for use inthe present invention are prepared by reacting corresponding nitrazaisocyanates, such as 3-nitrazal-butyl isocyanate, with aqueous strongmineral acid solutions, as more fully disclosed in my copending U.S.patent application Serial No. 666,273.

The above-mentioned nitraza isocyanates are prepared by reactingnitraza-acid halides, such as 4-nitrazapentanoyl chloride, with alkalior alkaline earth metal an'des, as for example sodium azide, or form thecorresponding nitraza azides and then heating said nitraza azides underanhydrous conditions to etfect rearrangement to the desired nitrazaisocyanates. This method of preparing nitraza isocyanates is more fullydisclosed in my copending U.S. patent application Serial No. 514,384,filed June 9, 1955.

The nitraza-acid halides from which the nitraza isocyanates are preparedare obtained by reacting thionyl halides, such as thionyl chloride, withappropriate nitrazaacids, as more fully dislosed in my copending U.S.patent application Serial No. 514,3 84. The nitraza-acids can benitroalkyl-aza-acids which are prepared by condensing nitroalcohols withamino acids, as more fully disclosed in assignees copending U.S. patentapplication Serial No. 416,385, filed March 15, 1954, oralkyl-nitraza-acids which are prepared by the acid hydrolysis ofnitraza-nitriles, as disclosed in my copending U.S. patent applicationSerial No. 514,386, filed June 9, 1955.

It should be pointed out that mixtures of suitable nitraza amines can beemployed in the preparation of the N,N'- bis (nitrazaalkyl) oxamideswhich are the starting materials in the present invention. It is thuswithin the purview of my invention to utilize N,N'- bis (nitrazaalkyl)oxamides of the general formula given in the reaction scheme, in whichthe two R's and/or the two A's are respectively different, with nitricacid, in accordance with the method of the present invention, therebyproducing N,N-bis (nitrazaalkyl)-N,N-dinitro oxamides of the generalformula claimed in which the Rs and/or the As are respectivelydifferent. For reasons of convenience and economy, however, I prefer touse N,N'-bis (nitrazaalkyl) oxamides which are symmetrical, i.e., thosein which the Rs and As are respectively equivalent, as startingmaterials in the practice of the present invention.

It is preferred to carry out the nitration reaction of this invention inthe presence of a dehydrating agent, such as sulfuric acid. Thedehydrating agent takes up the water of reaction thus shifting thereaction equilibrium to increase the yield. My invention is not limitedto the use of sulfuric acid as the dehydrating agent. Other conventionaldehydrating agents, such as acetic anhydride, phosphoric acid, or thelike, can be used in the practice of my invention.

It will be appreciated that a wide variety of high energy oxamidecompounds can be prepared in accordance with the method of my invention.For example, N,N'-bis (4-nitraza-1-hexyl) oxamide and N,N'-bis(3-aza-3,5,5- trinitro-l-hexyl) oxamide react with nitric acid, to yieldN,N'-bis (4-nitraza-l-hexyl)-N,N'-dinitro oxamide and N,N'-bis(3-aza-3,5,5-trinitro-l-hexyl)-N,N'-dinitro oxamide respectively. Othermembers of this new series of high energy oxamide compounds are preparedsimply by reacting appropriate starting materials as taught herein.

I claim:

1. As a new composition of matter, an N,N'-bis(nitrazaalkyl)-N,N'-dinitro oxamide having the formula:

NO: NO: (If NO: NO!

RCHr-I -IACHIILTCCI ICHrA-N-OHgR where each R is a radical selected fromthe group consisting of hydrogen, lower alkyl, and lower nitroalkylradicals and each A is a lower alkylene radical.

2. As a new composition of matter, an N,N'-bis(nitrazaalkyl)-N,N'-dinitro oxamide having the formula:

claim 1 in which each R is a 5. As a new composition of matter, N,N-bis(4-nitraza- 1-hcxy1)-N,N'-dinitro oxamide.

6. As a new composition of matter, N,N'-bis (B-aza-3,5,5-trinitro-l-hexyl) -N,N'-dinitro oxamide.

7. The method of preparing N,N-bis (nitrazaalkyn- N,N-dinitro oxamideshaving the formula:

N0: ITIO: 0 (I? 1110: N02

R-CHrl T-ACHaNi J-ON0Ha-AlLT-CH:R which comprises nitrating N,N'-bis(nitrazaalkyl) oxamides having the formula:

F r i i r t RCH1N-ACHr-NCCNCHr-AN-CHr-R with nitric acid; wherein each Ris a radical selected from the group consisting of hydrogen, loweralkyl, and lower nitroalkyl radicals, and each A is a lower alkyleneradical.

8. The method of preparing N,N'-bis (nitrazaa1kyl)- N,N'-dinitrooXamides having the formula:

N0 N01? (6 NO: N01

R-ILl-A-OH:NCCN-CH:A-N-R which comprises nitrating N,N'-bis(nitrazaalkyl) oxamides having the formula:

N0, H. 0 0 H No, R-I IAOH:-IlT l TCHIA-IIR with nitric acid; whereineach R is a lower alkyl radical and each A is a lower alkylene radical.

9. The method of claim 7 wherein each R is a lower nitroalkyl radical.

10. The method of preparing N,N-bis (S-nitraza-lbutyl)-N,N'-dinitrooxamide which comprises nitrating N,N'-bis (B-nitraza-l-butyl) oxarnidewith nitric acid.

11. The method of preparing N,N'-bis (4 nitraza-1- heXyl)-N,N'-dinitrooxamide which comprises nitrating N,N'-bis (4-nitraza-1-hexyl) oxamidewith nitric acid.

12. The method of preparing N,N'-bis (3-aza-3,S,5-trinitro-l-hexyl)-N,N'-dinitro oxamide which comprises nitrating N,N-bis(3-aza-3,5,5-trinitro-1-hexyl) oxamide with nitric acid.

13. The method of claim 7 in which the nitration reaction is carried outin the presence of a dehydrating agent.

14. The method of claim 10 in which the nitration reaction is carriedout in the presence of sulfuric acid.

No references cited.

1. AS A NEW COMPOSITION OF MATTER, AN N,N''-BIS(NITRAZAALKYL)-N,N''-DINITRO OXAMIDE HAVING THE FORMULA: